Display panel or portion thereof with a graphical user interface



The FIGURE is a front view of a display panel or portion thereof with a graphical user interface showing our new design.

The broken lines shown in the drawings, including the text, represent portions of the display panel or portion thereof with a graphical user interface that form no part of the claimed design, but illustrate the display environment. 

CLAIM The ornamental design for a display panel or portion thereof with a graphical user interface, as shown and described. 